Nuclear power produces a million times as much energy as fossil fuels, per pound of fuel, without producing pollution or affecting climate.

Less radiation has been released into the environment from all nuclear reactors combined, over the ~60 years we’ve used them, in normal operations and minor accidents and major accidents, than from a single year of using a single average coal plant. (Coal ash is classified as “naturally occurring radioactive material”, NORM, so it doesn’t have to be cleaned up).

People died in the Fukushima area from the earthquake and tsunami due to fires from coal, oil, gasoline, and natural gas. Nobody died (or is likely to die) from the nuclear reactor failures. One person was found dead at the reactors, from drowning.

As safe as our current reactors are, there are much safer reactor designs possible, that also produce dramatically less long-term nuclear waste. Some even use “nuclear waste” as fuel. Some have been built and tested. Yet we’re not using them, for political reasons and from inertia.

Our current reactors (light water reactors, LWR) use solid fuel in carefully prepared fuel rods, and are cooled with water. High temperature water must be kept under very high pressure, or it boils. Solid fuel traps fission byproducts, which stop fission with <2% of the fuel used; then the fuel rod has to be replaced. All the uranium and plutonium in the fuel rod, with all the fission byproducts, have to be stored for 100,000+ years.

Molten Salt Reactors (MSR), including Liquid Fluoride Thorium Reactors (LFTR), have molten fuel that circulates through the reactor, so over 99% of the fuel is fissioned, and continuously refueled.

Unlike water-cooled LWRs, LFTRs are cooled by molten salt, very good at transferring heat. The salt coolant is several hundred degrees below its boiling point, so the reactor runs at atmospheric pressure. The fuel is strongly chemically bound to the salt, so LFTRs have no chance of “loss of coolant accidents”. Since the salt doesn’t boil, LFTRs have no risk of high-pressure explosions.

In an emergency, or for scheduled maintenance, turn off cooling on a “freeze plug” and the fuel quickly drains to passive cooling tanks, where fission is not possible. Power is required to prevent the reactor shutting down. This could be controlled by operators, remote seismic sensors, temperature sensors.

In a LFTR, none of the waste is long-term. Fission byproducts are easily removed from the molten salt and safely stored. All have short half lives: 83% are safe in 10 years or less; 17% (135kg or 300lbs per 1 giga-watt-year electricity) are safe in 350 years. Elements with long half-lives stay in the reactor, where neutron bombardment causes them to fission or decay into elements with short half-lives. (LWR leaves 250,000kg waste to store for 100,000+ years, per 1GW-year. Wow! See LFTRs No Long-Term Waste Storage.)

There are three possible fuels for nuclear reactors: uranium-235 (0.7% of all U), uranium-233, plutonium-239. LFTRs can use all three. LFTRs can convert thorium (Th-232) to U-233, or convert U-238 (over 99.2% of all U) to Pu-239, inside the reactor, no fuel fabrication needed. LFTRs could eliminate (fission) long-term nuclear waste from LWRs.

Thorium is 4 times as abundant as uranium, and virtually 100% of naturally occurring thorium is Th-232. Thorium is found with rare earth elements, in coal (far more thorium energy in coal ash piles than energy from burning coal), and in some types of sand.

In a LFTR, the reactor is cooled by a molten salt (no water used). The heat from fission turns a turbine to make electricity (like in a LWR or coal plant, or with more efficient high-temperature turbines), and/or is used for high-temperature processes (for example, desalinating seawater or making vehicle fuels from CO2 and water).

With no high pressures, no water, and materials designed for high-temperature operation, LFTRs will be much less complex (and therefore less expensive) to build than LWRs. They can be factory assembled, with modern quality control, and shipped wherever needed. A 220 MW LFTR would fit in a standard shipping container (think “18-wheeler”), a few more for the fuel cooling tanks, waste processing, electric generator and gasoline-maker.

If you include all the start-to-finish costs of generating power (but not carbon tax, pollution cleanup, or health care costs of using fossil fuels), electricity from LFTRs would be less expensive than from coal or oil or natural gas, per gigawatt-year electricity. LFTRs also require very little land, and no water cooling, so can be located where electricity is needed, or even deployed for disaster relief.

Oak Ridge National Laboratories (ORNL) designed and built a Molten Salt Reactor from 1960-1965, and operated it for over 15,000 hours, see Molten Salt Reactor Experiment. They demonstrated the design worked, materials, equipment, procedures, operations, safety, use of different fuels. It was found to be an extremely stable reactor (rate of fission automatically regulated by the natural heat expansion/contraction of the molten fuel). They turned off the fan keeping the freeze-plug frozen on Friday nights, left for the weekend, reheated the fuel on Monday and pumped it back into the reactor.

With modern materials, computer-aided simulations and design tools, modern manufacturing techniques, modern instrumentation and testing, and all the ORNL experimental results, we could build LFTRs and then LFTR factories, in 5 years. ORNL designed and built a MSR (most of a LFTR, just without the “thorium blanket” to breed fuel) in 5 years, with slide rules and good engineers.

(The Nuclear Regulatory Commission says will take at least 20 years; but they don’t want MSRs to work, they want to keep LWRs going, and their high-power high-pay jobs; the NRC takes over 5 years to license a new reactor that is identical to another that was built. Maybe when China builds them and tries selling us LFTRs, the NRC will wake up?)

LFTRs are an excellent “baseload power” to combine with solar or wind power, and easily follow the electric demand (when wind/solar are producing electricity, LFTRs automatically generate less), to replace our using coal and oil.